Oocyte Growth and Maturation


Book Description

Studies of oogenesis occupy an important place in current in vestigations in developmental biology. Today no one has any doubt whatsoever that oogenesis is not just the prelude to development, but is development itself, and a very essential part of it. These words of an eminent Soviet scientist, B. L. As taurov , taken by T. B. Aizenshtadt as an epigraph to her chapter in this book, make a good epigraph for the entire book. It is now clear that during oogenesis not only vast reserves of ribosomes and mitochondria, of yolk, carbohydrates, and lipids, and of enzymes for protein and nucleic acid synthesis and for carbohydrate and fat metabolism (which ensures the energy supply and metabolism of the oocyte and the developing embryo) are formed, but also long-lived mRNA and proteins are synthesized, which determine both the completion of oocyte maturation and the initial stages of embryonic development. In the last 15-20 years, the use of molecular biology methods, electron microscopy, autoradiography, and microsurgical methods of experimental embryology in studying the pre-embryonic development of animals has greatly increased our knowledge of oogenesis. This has led to the need to systematize the data obtained, to reinter pret old ideas, and to review the results obtained by new research trends which have emerged in the last few years and which are of general biological interest. Such a task was undertaken in the book Sovremennye Problemy Oogeneza (Current Problems of Oogenesis), published in 1977 (in Russian).




Dynamics of the Mammalian Sperm Head


Book Description

Mammalian spermatozoa have complex structures. The structure-function relationship of sperm has been studied from various viewpoints. Accumulated evidence has shown that the sperm components undergo sequential changes from the beginning of spermatogenesis to the time of fertilization/embryogenesis. Structural analyses have been performed using various new techniques of light and electron microscopy as well as immunohistochemistry and immunocytochemistry in combination with specific probes such as antibodies against sperm components. Recently developed gene-manipulation techniques have accelerated investigations on the events that govern the relationship between the structure and molecular components of sperm. In addition, animal models with gene manipulations have been shown to exhibit various morphological and functional abnormalities that lead to infertility. In this book, I discuss the events that occur in the normal sperm head and govern the structure-function relationship from the time of spermatogenesis to that of fertilization or egg activation. In this regard, I describe dynamic modifications and maturation events occurring in sperm-head components and compare the outcomes of these events with the outcomes of their failure.




Hormonally Active Agents in the Environment


Book Description

Some investigators have hypothesized that estrogens and other hormonally active agents found in the environment might be involved in breast cancer increases and sperm count declines in humans as well as deformities and reproductive problems seen in wildlife. This book looks in detail at the science behind the ominous prospect of "estrogen mimics" threatening health and well-being, from the level of ecosystems and populations to individual people and animals. The committee identifies research needs and offers specific recommendations to decision-makers. This authoritative volume: Critically evaluates the literature on hormonally active agents in the environment and identifies known and suspected toxicologic mechanisms and effects of fish, wildlife, and humans. Examines whether and how exposure to hormonally active agents occursâ€"in diet, in pharmaceuticals, from industrial releases into the environmentâ€"and why the debate centers on estrogens. Identifies significant uncertainties, limitations of knowledge, and weaknesses in the scientific literature. The book presents a wealth of information and investigates a wide range of examples across the spectrum of life that might be related to these agents.




Drinking Water and Health,


Book Description

The most recent volume in the Drinking Water and Health series contains the results of a two-part study on the toxicity of drinking water contaminants. The first part examines current practices in risk assessment, identifies new noncancerous toxic responses to chemicals found in drinking water, and discusses the use of pharmacokinetic data to estimate the delivered dose and response. The second part of the book provides risk assessments for 14 specific compounds, 9 presented here for the first time.







Scientific Frontiers in Developmental Toxicology and Risk Assessment


Book Description

Scientific Frontiers in Developmental Toxicology and Risk Assessment reviews advances made during the last 10-15 years in fields such as developmental biology, molecular biology, and genetics. It describes a novel approach for how these advances might be used in combination with existing methodologies to further the understanding of mechanisms of developmental toxicity, to improve the assessment of chemicals for their ability to cause developmental toxicity, and to improve risk assessment for developmental defects. For example, based on the recent advances, even the smallest, simplest laboratory animals such as the fruit fly, roundworm, and zebrafish might be able to serve as developmental toxicological models for human biological systems. Use of such organisms might allow for rapid and inexpensive testing of large numbers of chemicals for their potential to cause developmental toxicity; presently, there are little or no developmental toxicity data available for the majority of natural and manufactured chemicals in use. This new approach to developmental toxicology and risk assessment will require simultaneous research on several fronts by experts from multiple scientific disciplines, including developmental toxicologists, developmental biologists, geneticists, epidemiologists, and biostatisticians.




Textbook of Clinical Embryology


Book Description

The success of Assisted Reproductive Technology is critically dependent upon the use of well optimized protocols, based upon sound scientific reasoning, empirical observations and evidence of clinical efficacy. Recently, the treatment of infertility has experienced a revolution, with the routine adoption of increasingly specialized molecular biological techniques and advanced methods for the manipulation of gametes and embryos. This textbook – inspired by the postgraduate degree program at the University of Oxford – guides students through the multidisciplinary syllabus essential to ART laboratory practice, from basic culture techniques and micromanipulation to laboratory management and quality assurance, and from endocrinology to molecular biology and research methods. Written for all levels of IVF practitioners, reproductive biologists and technologists involved in human reproductive science, it can be used as a reference manual for all IVF labs and as a textbook by undergraduates, advanced students, scientists and professionals involved in gamete, embryo or stem cell biology.




The Testis


Book Description




Exploring the Biological Contributions to Human Health


Book Description

It's obvious why only men develop prostate cancer and why only women get ovarian cancer. But it is not obvious why women are more likely to recover language ability after a stroke than men or why women are more apt to develop autoimmune diseases such as lupus. Sex differences in health throughout the lifespan have been documented. Exploring the Biological Contributions to Human Health begins to snap the pieces of the puzzle into place so that this knowledge can be used to improve health for both sexes. From behavior and cognition to metabolism and response to chemicals and infectious organisms, this book explores the health impact of sex (being male or female, according to reproductive organs and chromosomes) and gender (one's sense of self as male or female in society). Exploring the Biological Contributions to Human Health discusses basic biochemical differences in the cells of males and females and health variability between the sexes from conception throughout life. The book identifies key research needs and opportunities and addresses barriers to research. Exploring the Biological Contributions to Human Health will be important to health policy makers, basic, applied, and clinical researchers, educators, providers, and journalists-while being very accessible to interested lay readers.